Mitchell Institute for Fundamental Physics & Astronomy
College Station, Texas 77843
I will discuss a novel proposal for transitioning the background geometry (including NS5-branes and holomorphic, slope-stable vector bundles) of 4-dimensional, N = 1 heterotic string compactifications through conifold transitions connecting Calabi-Yau threefolds. The proposal is geometric in nature and utilizes a description of how the cotangent bundles of the deformation and resolution manifolds in the conifold can be connected by an apparent small instanton transition involving a five-brane wrapping the small resolution curves. Given this, a “pair creation” process will be proposed in which five-branes can be generated simultaneously in the gauge and gravitational sectors and used to describe a coupled minimal change in the manifold and gauge bundle. This analysis leads to classes of what seem to be dualities which we then confirm at the level of spectrum in large sets of examples. While the duality is novel when five-branes are involved, it reduces to the Target Space Duality exhibited by (0, 2) GLSMs in the case of compactifications involving only gauge bundles.